Solve for $t$ : $25 + t = 10$
Solution: Subtract $25$ from both sides: $ \begin{eqnarray} \\ 25 + t &=& 10 \\ \\ {-25} && {-25} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{25 + t} &\hphantom{=}& \hphantom{10} \\ t &=& 10 {- 25} \\ \end{eqnarray} $ Simplify. $ t = -15$